cjxl_bisect_bpp (1597B)
1 #!/bin/sh 2 # 3 # Copyright (c) the JPEG XL Project Authors. All rights reserved. 4 # 5 # Use of this source code is governed by a BSD-style 6 # license that can be found in the LICENSE file. 7 # 8 # Bisects JPEG XL encoding quality parameter to reach a given 9 # target bits-per-pixel value. 10 # (To be used directly, or as a template for tailored processing.) 11 # 12 # Usage: cjxl_bisect_size {input_filename} {output_filename} {target_bpp} 13 14 # 15 # We take the `bisector` tool from $PATH, or, if not available, 16 # try to locate it in the same directory as the current script. 17 # The `get_bpp` helper is taken from the same directory as the current script. 18 # 19 20 input_filename=$1 21 output_filename=$2 22 target_size=$3 23 24 script_dir=$(dirname $(readlink -f $0)) 25 bisect_tool=$(which bisector) 26 if [ -z $bisect_tool ] ; then 27 bisect_tool="${script_dir}/bisector" 28 fi 29 jxl_get_bpp_helper="${script_dir}/jxl_get_bpp_helper" 30 # If $CJXL_BIN is set, we use this instead of looking for `cjxl` on $PATH. 31 32 cjxl_bin=${CJXL_BIN} 33 if [ -z $cjxl_bin ] ; then 34 cjxl_bin="cjxl" 35 fi 36 37 # Using `identify` from ImageMagick here. 38 num_pixels=$(identify -format "%w*%h\n" /tmp/baseball.png|bc) 39 40 # Allow 0.5% tolerance in size (--rtol=0.005). 41 exec $bisect_tool --var=BISECT --range=0.01,15.0 --target=$target_size \ 42 --rtol_val=0.005 \ 43 --cmd="$cjxl_bin --distance=\$BISECT ${input_filename} ${output_filename}_bisect_\$BISECT.jxl ; (find ${output_filename}_bisect_\$BISECT.jxl -printf \"scale=10;%s/$num_pixels\n\" | bc -l)" \ 44 --final="mv ${output_filename}_bisect_\$BISECT.jxl ${output_filename}; rm -f ${output_filename}_bisect_*.jxl" \ 45 --verbosity=1